The participation of human papillomaviruses in the development of cervical cancer is supported by the demonstration in the tumor cells of papillomavirus group-specific antigen and viral particles. In this project we will attempt to induce neoplastic progression of papillomavirus-infected lesions of human cervix by treating the grafts with agents which may represent additional risk factors for the development of cervical cancer. Some of these agents include benzopyrene, n-methylnitrosamine, estrogens, and herpes simplex virus type 2.